Two Pole Switches Used to Control Two Different Circuits

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scottbrown

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I had a question posed to me that I'm unable to find a satisfactory answer for. Is it allowable per the NEC to use a single two pole snap switch in a restroom to control the light circuit and the exhaust fan circuit if the lights and the fan are fed from two separate circuit breakers in the same panel? My response would be no simply because you could turn off the breaker for either the fan or the lights and you would still have one side of the device energized. This would seem to be a safety hazard, but I would like to find chapter and verse that states one way or the other. Thanks in advance.
 
Re: Two Pole Switches Used to Control Two Different Circuits

I would say that the need for a 2 pole breaker cannot be satisfied with circuits from two different panels so you are correct. Also I believe that the UL listing of a two pole device is only for use with one circuit.
 
Re: Two Pole Switches Used to Control Two Different Circuits

I have to amend my first post. I assumed that the circuits were from different panels. Unless there is a listing issue, two circuits fed from a 2 pole CB would be permitted since it would disconnect both circuits simultaneously when they are on the same yoke of one device.
 
Re: Two Pole Switches Used to Control Two Different Circuits

Sorry, I needed to be more specific. The two circuits are being fed from two different single pole circuit breakers.

Thanks again.
 
Re: Two Pole Switches Used to Control Two Different Circuits

The closest I could find was 210.4(B). But I would not say the switch is a device that is being "supplied" by the two circuits, and I have no idea whether any part of a switch can be properly called a "yoke." But the "intent" of 210.4(B), meaning "the thing that that article is trying to prevent," is exactly the same as the situation you are describing.
 
Re: Two Pole Switches Used to Control Two Different Circuits

Charlie,

It also says 'supplied by a multiwire branch circuit'. I'd have to say that this situation is allowed.
 
Re: Two Pole Switches Used to Control Two Different Circuits

According to UL guide WJQR:
Multi-pole, general use snap switches have not been investigated for more than single circuit operation unless marked ??2-circuit?? or ??3-circuit.??
 
Re: Two Pole Switches Used to Control Two Different Circuits

Originally posted by paul:I'd have to say that this situation is allowed.
Click to expand...
I would too, but only if the two circuits are fed by a breaker that would simultaneously open both circuits. In this case, they are fed by separate single pole breakers. I don't think that is safe. I am just not certain that 210.4(B) can be used as the basis for calling it a violation.
 
Re: Two Pole Switches Used to Control Two Different Circuits

I don't think that is safe. I am just not certain that 210.4(B) can be used as the basis for calling it a violation
Click to expand...
Charlie, are you saying this because it is not a multiwire branch circuit as mentioned in 210.4(B)?
 
Re: Two Pole Switches Used to Control Two Different Circuits

No, it's a multiwire branch circuit. But is any part of the 2-pole switch properly called a "yoke"? Also, that section talks about a device being supplied by two circuits. The switch is not the thing being "supplied." Rather, the switch is in the path between the two circuit breakers and the two loads. Given those two issues, does 210.4(B) apply or not? I am not certain.
 
Re: Two Pole Switches Used to Control Two Different Circuits

Originally posted by charlie b:
But is any part of the 2-pole switch properly called a "yoke"?
Click to expand...
I believe the mounting strap is properly called the yoke.

Also, 210.4(B) only applies to dwelling units. (At least in the '02, I don't have the '05 yet)

The OP said "restroom" which leads me to believe this is not a dwelling unit.
 
Re: Two Pole Switches Used to Control Two Different Circuits

device1122.jpg


http://www.levitonhelpdesk.com/catalog/default.asp?frame=productdisplayprint&PrintPreview=True&screen=productdisplayprint&RecKey=3877&ConnectRecKey=

Here is a two pole switch with one yoke.

I'm curious as to how we know that this is fed from a multiwire circuit and not two circuits with two neutrals?
 
Re: Two Pole Switches Used to Control Two Different Circuits

You wouldn't question it at all if you had twenty single pole CBs feeding twenty single or even multi-wire circuits to 100 stadium lights that were controlled by relays in a single panel. Why question the 2 CBs feeding a SPDT switch? Don't you test for voltage? I do. I grab the switch by the connected wires, and, if it hurts like h___, then I turn off the CB by shorting the wires with my screwdriver.
 
Re: Two Pole Switches Used to Control Two Different Circuits

Dcott, I'd have to say that this is allowed as long as the two circuits are fed from a two-pole breaker or two single-pole breakers that have a hanlde tie. Another option (if they're the same voltage (here's another can o' worms!)) is to rewire so the light and fan are fed from one circuit.

I used two 2-pole switches in this manner a while back, for the men's and women's bathrooms. I switched the lights separately in each room as usual, using one pole on each switch, but paralleled the single fan's switched leg using the second pole of each switch. I made an 'or' gate.
 
Re: Two Pole Switches Used to Control Two Different Circuits

Bad news guys, UL does not list all two pole switches to control two separate circuits.

UL White Book
SNAP SWITCHES (WJQR)
Multi-pole, general use snap switches have not been investigated for more than single circuit operation unless marked ??2-circuit?? or ??3-circuit.??
Click to expand...
Keep in mind a multiwire branch circuit can be considered one circuit.
 
Re: Two Pole Switches Used to Control Two Different Circuits

"The switch is not the thing being "supplied." Rather, the switch is in the path between the two circuit breakers and the two loads."
Charlie if the switch is in the path between two circuit breakers then a switch in a afci circut is also in the path between the CB and the receptacle outlet so it counts as an integral part of the same or am I reading something into it that isn`t there :D
 
Re: Two Pole Switches Used to Control Two Different Circuits

Bob this was pointed out already but everyone just seemed to glide right past it.
 
Re: Two Pole Switches Used to Control Two Different Circuits

Originally posted by electricmanscott:
Bob this was pointed out already but everyone just seemed to glide right past it.
Click to expand...
Yeah after I posted I went back and read more of the posts.

That aside maybe another time is needed in order for it to stick.

Originally posted by iwire:
Bad news guys, UL does not list all two pole switches to control two separate circuits.

UL White Book
SNAP SWITCHES (WJQR)
Multi-pole, general use snap switches have not been investigated for more than single circuit operation unless marked ??2-circuit?? or ??3-circuit.??
Click to expand...
Keep in mind a multiwire branch circuit can be considered one circuit.
Click to expand...
 
Re: Two Pole Switches Used to Control Two Different Circuits

Another aspect, if I remember correctly...you cannot do this if you are supplying 277 volt lighting. It would mean 480 would be present within the switch housing.

I know this doesn't really address your situation, but it does beg the question....are 2 pole switches rated for 277? and if yes...in what scenario could they be used? :p
 
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